Telephone-signal



(No Model.)

' T. A. WATSON.-

' Telephone Signal.

No. 240,208. I Patented Apru z lssa.

WihlEEEE. v IVETlhIII NPETERS. PHDT-LIYHOGRAPNER, WASRINGTOMD C PATENT FTeE.

THOMAS A. WATSON, OF EVERETT, MASSACHUSETTS.

TELEPHONE-SIGNAL.

SPECIFICATION forming part of Letters Patent No. 240,208, dated April 12, 1881.

Application filed J une 21, 1880.

To all whom it may concern Be it known that I, THOMAS A. WATSON, of Everett, county of Middlesex, State of Massachusetts, have invented an 1m provement in Telephone-Signals, of which the following description, in connection with the accompanying drawings, is a specification.

My invention relates to telephone-signaling,

and has for its object to enable an audible signal, sufliciently loud and of such distinctive character'as to readily attract attention, to be given by the usual telephonic instrument, thereby obviating the necessity of bells or other expensive apparatus for signaling.

In one embodiment of my present invention the case of the usual microphone or battery transmitter, in which both electrodes are suspended by flexible supports, is provided with a whistle so placed as to be conveniently blown by the operator, and adapted to impart a strong "ibration to the diaphragm of the said transmitter, which will thus transmit the sound to the receiving-telephones in the usualmanner. This kind of transmitter will give especially good results, as the vibrations of the musical instrument will be conveyed to both electrodes, thereby greatly increasing the efi'ect.

It will sometimes be preferable to set the diaphragm in vibration directly by the sonorous column of air in the whistle, instead of transmitting the said vibrations in the usual manner through the air inclosed in the case of the microphone; and to accomplish this I preferably make use of a form of diaphragm or vibrator invented by G. L. Anders, in which two plates are fastened together at their edges, which are free to vibrate, the middle of one of the said plates being fixed upon a support. As herein shown, the said plate would be sup ported at the end of the whistle which would open into the space between the two plates, the column of air in its vibrations impinging directly upon the other plate, which acts on the electrodes of the microphone in the usual manner. I When the transmitteris to be used only for signaling, a whistle and diaphragm of this kind may be permanently connected with the frame-work supporting the electrodes; or when the transmitter is to be used for speaking, a whistle open at its end may be inserted in the mouth-piece for signaling, and removed while the transmitter is used for talking.

(No model.)

It is well known that a musical note or continuous sound of uniform pitch transmitted to a receiving-telephone by electrical pulsations in the usual manner will cause strong vibrationsin the said telephone-diaphragm, emitting sounds that can be heard at a considerable distance, and this sound is especially loud when the note is in accord with thefundamental tone of the diaphragm of the said telephone. The shrill tone of a common whistle will give a signal as well adapted to call attention as the ordin ary bell, and is especially adapted for private lines, where an individual system is not required, and where it is desirable to have as little apparatus as possible.

Figure 1 is a front view of a microphonetransmitter provided with a whistle for signaling in accordance with my invention. Fig. 2 is a side view thereof; and Fig. 3, a sectional view, showingan arrangement to adapt the diaphragm to be directly vibrated by the sonorous column of air. Fig. 4 is a similar View, showing an ordinary form of diaphragm and mouthpiece, with a detachable whistle.

Figs. 1 and 2 illustrate the simplest embodiment of my invention.

A whistle, a, of proper sort to give a sharp shrill tone, and preferably made to harmonize with the natural or fundamental tone of the receiving-telephone by which the signal is to be sounded, is inserted in the case b of a microphone or carbon transmitter of any usual form in such position as not to interfere with the apparatus in the said case. That portion of the whistle to containing the sonorous column of air--or, in other words, the sounding part thereof-is wholly within the case b, and the sound-waves are transmitted by the air in the case to the diaphragm of the transmitter,upon which they act with great intensity, owing to the directness of such transmission.

The mouth-piece c of the whistle is extended outside the case to enable the operator to sound it readily, and, if desired, a flexible tube, d, and mouth-piece 6 thereon may be used for greater convenience in blowing the whistle.

In Fig. 3 the whistle a. is shown in section attached to the frame-work f supporting the diaphragm and electrodes of a microphone of common construction. The diaphragm shown is not of my invention, and is of peculiar construction, especially adapted to be vibrated by the column of air of a whistle or other musical instrument. It consists of two plates, m a, connected together at their edges, an annular ring or washer, 0, being inserted between them, and the said edges being free to vibrate. The plate on is provided with a central opening, at the edges of which it is connected with a tube, 19, forming a continuation of the whistle to. The column of air in the whistle a and tube 19 extends through the opening in the plate m, and in vibrating impinges strongly upon the plate a, setting it in vibration inunison with the said column of air. The plate 42, in its vibration, acts in the usual manner on the electrodes, causing aseries of electric impulses to be transmitted, which, in turn, vibrate the diaphragm of the receiving-telephone in unison with the column of air in the whistle a in the usual manner, causing the said telephone to give out a loud sound, sufficient to attract attention, for signaling purposes.

v If desired, the whistle a, Fig. 3, can be removed and the transmitter used for talking.

A whistle or similar instrument may be placed, as shown in Fig. 3, in the sound-passage leading to a diaphragm of common construction, and a whistle with an open end, as shown in Fig. 3, maybe used with a transmitting-instrument of any kind, the said whistle being fitted to the mouth-piece of the said transmitting-instrument, so that when inserted therein the column of air in the said whistle acts directly on the diaphragm.

The whistle may have its end fitted to the mouth-piece of the telephone surrounded with suitable material, such as cork or soft rubber, to enable it to be inserted tightly when desired to signal, and then be removed after the manner of a stopper; and the whistle may be connected with the telephone by a string or chain, to insure that it will always be at hand when wanted. This arrangement is shown in Fig. 4, the letters indicating the same parts as on other figures.

I claim 1. A battery-transmitter having both electrodes suspended by flexible supports and provided with an inclosing-case and whistle or musical instrument connected with said case.

2. A diaphragm composed of two plates connected together at the edges so as to leave a space between, in combination with a tube connected with a musical instrument and opening into said space.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

THOMAS A. WATSON.

Witnesses:

J os. P. LIVERMORE, N. E. O. WHITNEY. 

